Osborn p



(No Model.)l

O. P` LOOMIS. INGANDESGENT LAMP SOCKET.

No. 412,962. Patented Oct. 15,,1889.

W'Ltmmof I /m/d W W UNITED STATESV PATEN'r Orrice.

OSBORN P. LOOMIS, OF SOMERVILLE, MASSACHUSETTS, ASSIGNOR TO THE LOOMISELECTRIC MANUFACTURING COMPANY, CF NEVV YORK, N. Y.

INCANDESCENT-LAMP sooKET,

SPECIFICATION forming' part of Letters Patent NO. 412,962, dateclOctober 15, 1889.

Application filed September 3, 1888. erial No1 284,398. (No model.)

T0 aZZ whompzt may concern:

Be it known that I, OSBORN P. LOQMIS, a citizen of the United States,residing at Somerville, in the county of Middlesex and State ofMassachusetts, have invented certain new and useful Improvements inIncandescent Electric Lamps, of which the following is such a full,clear, and exact description as will enable any one skilled in the artto which it appertains to make and use the same, reference being had tothe accompanying drawings, forming part of this specification. a

My invention relates to an incandescent electric lamp having the springcontacts, which are connected to line, engaging with a firm contact orpressure the lamp-terminals, which I preferably locate on the stem ofthe lamp when the lamp-stem is set in the lamp socket or holder, andhaving a non-conducting guide-plate disposed within the lampsocket fordirecting the lamp-terminals to the said spring-contacts, the platepresenting a complete non-conducting outer face and acting as a shieldfor the parts of the lamp in circuit to prevent false contact of thelampterminals When the lamp is being put together; and the inventionfurther relates to the novel form of spring-contacts and to thekey-switch for admitting the current to the lamp and shutting it offtherefrom, the switch comprising a peculiar switch-block having alimited rotary play on the key-shank and embraced by two springcontact-fingers, so as to automatically operate with a shifting snapaction under the spring-power of the contact- 'fingers, all ashereinafter fully described, and 'then pointed out in the claims.

The objects of my invention are to guide the lamp-terminals withcertainty onto the spring-contacts, to prevent the possibility ofl falsecontact of the lamp-terminals with any parts of the lamp in circuit whenthe lamp is being put together, and to maintain a iirrn 4and thereforemore perfect contact between the same, and to have the key-switch onlypartly under control of the Operating-key, so that upon the initialmovement of the key the switch will'at first respond thereto and willthen act independently thereof; and a further object of the invention isto provide a neat and compact connection between the key-switch and thelamp-terminal.

In the accompanying drawings, in which like numbers of referencedesignate like and corresponding parts throughout, I have illustrated myinventiou as embodied in an incandescent lamp.

Figure 1 is a sectional view of the complete lamp, taken on ay planethrough the longitudinal axis thereof, as indicated by line 1 1, Fig. 3.Fig. 2 is alongitudinal sectional View of the lamp socket or holderhaving, in addition to the devices shown in Fig. 1, a part of theline-connection, the section being taken at right angles to that in Fig.1, as indicated by line 2 2 in Fig. 3. Fig. 3 is a transverse sectionalview of the lamp socket or holder, taken on line 3 3, Fig. 1. Fig. 4 isan enlarged detached cross-sectional view of the switchblock, the planeof the section being indicated by line 1 1, Fig. 3.

Referring to the drawings, 6 designates the lamp-globe, having anordinary form of stem 7, through which pass the leading-in wires 8 tothe filament 9 within the gloloe. The stem or butt 7 of the lamp isprovided with an insulating-plate 10, and in this stem are fiXed thelamp-terminals 11 and 12, which are electrically connected With theleading-in wires, respectively. These lamp-terminals are, by preference,located equidistant from the axis of the lamp-stem and project parallelthereto.

The parts just described are arranged together, and the stem 7 isremovably set in the tubular cylindricallamp-socket or holder 13 bymeans of a bayonet-joint consisting in the studs 14 on the stem and thelslots 15 formed in the holder.

Within the lamp-socket 13, and near the butt-end thereof7 is a disk 16,made of suitable insulating material and formed with an opening 17 forthe line-wires 18 to pass through, and this disk is rigidly attached tothe guide-plate 19, also made of suitable insulating material, by meansof the intermediate bracket 20, which has its ends secured to the disk'and guide-plate, respectively, by screws, as shown in Fig. 1.

In the bracket 20 is preferably journaled the rotative key 21, whichextcnds through the socket-piece and is provided with the usual handleupon the outer end. This key operates the controlling-switch of thelamp, and through its Operations the current is admitted to and shut offfrom the lamp. The switch-block, 22 is inounted on the inner end of thekey 21 in such a manner as to permit it to be partially rotated thereonin either direction relatively to t-he axis of the key. Any suitableconstruction may be adopted in inounting the switch-block on the key, sothat it may have the requisite rotative play thereon. In theconstruction here adopted the key-shank, which is formed with theenlarged transverse perforation 23,is passed centrally through theblock, which is made of a suitable insulating material. passed throughthe center of the block at right angles to the key-shank, so as toextend loosely through the opening 23 of the shank, the opening beingconsiderably greater in diameter than the diameterof pin 24, as shown inFig. 4, from which view it is evident that the switch-block may bepartially rotated on the key-shank to either side of the position thereshown, so as to throw the pin 24 out of the Vertical without moving thekey. By this construction the movements of the switchblock are renderedpartly independent of those of the key. Two of the opposite faces of theswitch-block 22, lying parallel to the axis of the key, are providedwith the contact-plates 25 and 26, respectively, and these plates are inelectrical communication through pin 24.l

The switch-block 22 is embraced by two spring contact-fingers 27 and 28,which are so disposed that the rotation of the switchblock willalternately break and establish the electrical connection between thefingers by bringing them alternately in contact with the bare insulatingmaterial of the block and then the respective contact-plates in anobvious manner. Vhen the Spring-fingers 27 28 are in contact with thefiat sides of the switch-block, they are, of course, under the 'leasttension. N ow, as the key is rotated in either direction theswitch-block will take up its movement because of the fiXed pin 24taking against the diagonally-opposite edges of the opening 23. (SeeFig.` 4.) As the block rotates, the tension of the contact-fingers willobviously increase until the diagonal or oblique axis of the block isbrought perpendicularly between the two fingers, when the tensionthereof becomes the greatest. The edges of the block being rounded, asshown at 37, Fig. 4, the spring contact-fingers will now quickly snapthe block through one-eighth of a revolution and bring the fiat facesthereof between and in contact with the fingers. Thus the spring-fingerswill automatically turn the block independently-of the key upon which itis mounted. In this way the'sWitch, whether in the opening or closing ofthe same, is always operated with the same quick and positive movement,and

A pin 24 is alsois at such time rendered wholly independent of the key,and consequently of the person Operating the key, so that thecontact-plates areautomatically moved into and out of connection withthe respective fingers at the same time, which is a manifest advantagein incandescent lighting where a high-tension current is used.

The contact-finger 27-the upper one in the views-is in electricalconnection with the line 18 through means of the binding-post v29, whichis secured to the non-conducting plate 16 by a screw, as shown in Fig.2. The contact-finger 28 is fastened to the guideplate 19 by screw 30,and the other end or wing thereof constitutes the spring-contact 31,which projects over the guide-perforation 32 of plate 19 and engageswith the lampterminal 12, the other lamp-terminal 11 being engaged bythe spring-contact 33, which is likewise fastened on the inner face ofthe plate 19 and extends over the opening 34 thereof, and is connectedto line by the binding-post 35, which by means of screw 36 clamps thecontact 33 to the guide-plate.

The guide-perforations 32 and 34 are disposed so as to easily receivethe projecting lamp-terminals 11 and- 12, respectively, and are much toolarge therefor, in order to permit the ready looking and unlocking ofthe bayonet-joint arranged between the lampstem and socket.

The contacts 27 and 28 engage the lampterminals with a firmspring-pressure, and a good connection is thereby insured, and therubbing of the terminals against the contacts in separating and puttingtogether the lamp will keep the contacting surfaces of both said partsclean, so as to always give a perfect electrical contact.

It is to be observed that the outer face of the guide-plate 19 acts as ashield to prevent false contact between the terminals 11 and 12 and anyparts of the apparatus within the lamp-socket which nia-y be in circuitwhen the lamp is being put together, since the heads of the severalscrews 30 36 for holding the'contacts of the terininals are embedded inthe plate, so as not to be exposed to the exterior thereof. Thus allliability of false contact is wholly avoided, for the lamp-termin alscan only make' electrical contact when they are properly passed throughthe guideperforations 32 and 34 and engage the springcontacts on theother side of the plate.

In Fig. 1, showing the complete lamp, the current is on the lamp, and itmay be supposed to enter from the line 18 by bindingpost 29 and to leadover the switch contactfinger 27, contact-plate 25, pin 24, contactplate26, finger 28, the terminal-contact 31, lamp-terminal 11, over one ofthe leading-in wires 8 and the filament 9, thence over the otherleading-in wire, terminal 12, contact 33, and to pass out by thebinding-post 35.

Having thus described my improvements in incandescent electrical lamps,what I claim IOO IIO

as new, and desire to secure by Letters Patent, isv 1. In anincandescent electric lamp, the combination, with the lamp-stem 7,having the lamp-terminals 11 and 12 mounted thereon and connected to theleading-in wires and proj ecting` from the face of the lamp-stem, of alamp-socket 13, adapted to receive and hold the said lamp-stem, andprovided With the guide-plate 19, prescnting au insulating surface orface toward the lamp-stem, said guideplate formed With suitableperforations 32 and 34, for receiving the lamp-terminals 12 and 11,respectively, and the spring-contacts 31 and 33,n1ounted Within thelamp-socket 13 r and connectedl to line, the said contacts arranged tothe opposite side of said guide-plate from Where the lamp-terminale areentered and having their free ends disposed so as to extend transverselyacross the perforations 32 and 34 of the guide-plate 19 and nearthereto, so as to engage with spring-pressure the flat ends of thelamp-terminals 11 and 12, respectively, When the lamp is put together,substantially as and for the purpose set forth.

2. In an incandescent electric lamp, the combination, With a pair ofsuitably-spaced spring contact-fingers 27 and 28, connected to line, ofa switch-key 21, mounted to rotate in its bearings and having its shankformed with a transverse opening 23, a-switch-block 22, made ofinsulating material and loosely mounted on the shank of the key 21 andcovering the opening 23 thereof, a fixed metallic pin 24, extendingtransversely through the block 22 and passing through the opening 23 ofthe key-shank, the diameter of the pin 24 being considerably less thanthat of opening 23 to give the necessary lost motion to theswitch-block, and the con tact-plates 25 and 2G, mounted, respectively,upon opposite sides of the switch-block and in electric communicationthrough means of the pin 24, the said block being embraced by the saidcontactcombination, with the lamp-Stein 7, having the lamp-terminals 11and 12,l of the lampsocket 13, adapted to receive and sustain the saidstem in position, the non-conducting` guide-plate 19, formed With theguide-perforations 32 and 34, the contacts 31 and 33 for thelamp-terminals, such contacts being secured to the guide-plate by screws30 and 36, respectively, and the screws having their heads embedded inthe said plate, so as not to be exposed upon the outer face thereof,substantially as and for the purpose set forth. 4. In an incandescentelectric lamp, the combination, With the lamp-stem 7, having thelainp-terminals 11 and 12 proj ectin g therefrom, of the lamp-socket 13,adapted to 1'e-" ceive said lamp-stem, a lock for uniting` the socketand stem, such lock operated by turning said stem on its axis, theinsulating guide-plate 19, located Within said socket and provided Withthe perforations 3.J 34, arranged to correspond With the disposition. ofsaid lamp-terminals which enter therethrough and having a diameterconsiderably greater than the dianieter of said terminals, Whereby thelamp-stem may be turned on its axis to lock and unlock the stem andsocket, and the spring-contacts 31 33, engaging With firmspring-pressure the said lamp-terminale When the same are enteredthrough the perforations of the guide-plate and the stem and socket areunited, substantially as and for the purpose set forth. W

In testimony Whereof I have hereunto set my hand and seal, this 20th dayof August, 1888, in the presence of the two subscribing witnesses. I

OSBORN P. LOOMIS. [L. s.] Witnesses: p

CHAs. H. PIERcE, Bom). N. CLARK.

